Vacuum fuel-feeding system



W. O. CHASE ACUUM FUEL FEEDING SYSTEM' Nov. 1 1927.

original Filed 001:. 8, 1921 2- Sheets-Shed?. 1

nl a u l MU @www Nov.` l l, 1927.

` 1,647,174 w. o. CHASE VACUUM FUEL FEEDING SYSTEM Original Filed Oct. 8, 1921 2 Sheets-Sheet 2 Patented Nov. 1 1927.

UNITED` sTATEs WILFRED o. CHASE, or BEDFORD, MICHIGAN," Assn-mon To srEwAn'r WARNER y srnnnoivrnfrnn CORPORATION, or CHICAGO, ILLINOIS, A ooRPonATIoNfoF' VIR- Y GINIA.

PATENT OFFICE.

`VACTUUIVI FUEL-FEEDIG Application filed october s, 1921, seriarnmeoaaee. Renewed March 2o, 192e'.-

The invention relates to vacuum feeding systems and has for its object simplifying the construction and impro-ving and rendering more certain'the Operation.

c Tn the present state of the art various constructions of vacuum feeding apparatus have been devised, all of which have certain elements in common. Thus there is present in each construction a low level tank, a

ir high level or vacuum tank usually having two compartments, the upper compartment being directly connected with the low level tank and having a gravity discharge connec. tion to the lower compartment controlled by 1F a normally closed check-valve, a suction connection between the intake manifold of the engine and the upper chamber, an air inlet for the upper chamber and valves whichalternatively open and close the suction and air 2U inlet connections, the Operating mechanism for these valves consisting of a float arranged in the upper chamber together with a lever and spring mechanism by which the movement of the oat will at predetermined upper and lower levels cause a reversal of the valves. Thus the upper 'chamber will periodically receive fuel from the lower tank and discharge the fuel to the lower compartment of theA upper tank and from which it so is fed by gravity to the carburetor of the engine.

TV ith the construction as just `described the shifting of the valves is due vsolely to the actuation of the float by the rise and fall 33 of the liquid between exactly predetermined levels. @n the other hand, the lifting of the liquid is due to the suction, which varies according to the vacuum in the manifold'. Tn the ordinary operation of a motor car 4H there is a wide range of variation in manifold pressures, the highest vacuum being when the Vengine is idling and the lowest where the throttle is wide 4open and the engine is operating under heavy load. `Such 4.5 variation occasions a corresponding variation` in the elevationof the fuel and the time when there is the least power for elevating Vthe same. Moreover, the air which is withdrawn fromvthe vacuum chamber of the tank carries with it vapor of the liquid fuel and the higher the vacuum in the tank the greater the vaporization, and conse-y quently, the richer the mixture produced. It is the function of the carburetor of the chamber; and

engine to properly proportion the ratio -fuel Yto-air, and therefore, the mixture which is withdrawn from the vacuum tanky and which varies in richness interferes with proper carburetion and proper operation of the engine. A further disturbance is occasioned by the alteration in the` manifold pressures Vdue to the alternating introduction of air from the vacuum tank and the cutting off of such supply of air.

It is the primary object of my invention to overcome thelack of uniformity in action dueto the. varying causes above described, and it is the further Object to greatly simplify the mechanical construction. Thus, in place of operating the valves through a complex lever and spring mechanism actuatedV solely by the buoyancy of the float, I dispense with all levers and springs and control the valves through the conjoint action of hydrostatic. and pneumatic pressures. Thisnot only disaenses with numerous parts, but also avoids the large variations in action between low vacuum and high vacuum conditions in the manifold incident to the normal voperation of the engine.

Another feature of improvement is in the connection between the upper and lower chambers of the vacuum tank. vIn this I have substituted for the normally closed check-valve a normally open valve which has the advantages; first, that the two chambers are normally in open communication and` any expansion of liquid in the lower chamber will merely force it upward in' the upper chamber; second, there is less restriction to the flow of liquid so that the discharge from the upper to the lower tankis more rapid; third, there is no danger of the clogging of the valve by foreign matter lodging betweenA the same and its seat; fourth, the construction is simpler and can be manufactured at a lower cost. Other features'of improvement will be more specifically referred to hereinafter.

In the drawings:

Figure l is a sectional elevation of the tank with the parts in position where the i upper chamber is empty of liquid;

Figure 2 is a similar view showing the parts in normal position of Operation when the vacuum is in communication with the Figure 3 is a similar view of the parts in normal operation where the atmospheric air is in communication with the chamber.

A istlie vacuum tank which hasarianged in the upper portion thereof the inner receptacle B `ofsmaller` diameter, leaving an.

annular .chaii'iberC "between thev same and the' outer tank and connected tothe latter at its upper end by the flange D. E is a4 cap or head for closing both tanks, which is suitably bored .and` chambered :for the, reception of the controlling valves and their connections;

lVithin the inner receptacle B is arrangeda float F: which. is preferably only about'one halfthe weight of the displaced liquid'. The

float E is mounted upon a Vvertically extending stem, Gr, this being guided at its lower end'iii' a suitable bearing Hand at itsl upper end in a bearing l formed in the head E;

The upper end of-the stein forms a, valve J which engages a seat'l. in the head yE controlling the Avacuum connection, The area ofntlievseat K and ithe opening 'therethrough'-` is such that when the valve 'is seated and there is atmospheric pressure within the receptacle B,- the differential pressure acting uponttlie valve will supplement the fiota-' tion pressureyofvthe liquid'in sustaining` the float. Thus` the liquid within the receptacle.

i3l may fall-to a ccnsiderable distance belowthey displacement levelon the float be forethe weight of the latter will overcome theY differential airA pressure and withdrawI the valveJ from the seat K;

L isa 'valve' within a chamber in the head E which is gravity-seated and lcontrols an air vent port M for the r-eceptacle B; This port M communicates with a passage N in the head which is connected with adownturned conduit O` outside. of the tanl; Vand also communicates through a ychan-'nel P with the annular 'chamber C, between the tanks: A f'and B;- The vvalve L is piieumatically operated and to this en d is provided with a pistonportion L whichI is slidable in the cylindrical portion of the casing, while above this piston portion is a valvevface L2 for engagging a. seat Q.- This seat, is formed on a plug' Q whichfornis a closure for the chamber containing thelvalve L, and thep'ort Q2y within theseat is connected by a passage Q3 with a chamber lV-ithin this chamberV is a valve S which isguided yin a hollow T will, when either of the valves S or J is seated, cause a.. differential air pressure thereonA cerrespondiiig toy the area, o'ftheir respective seats. The valve J is provided with l an upward .extension V, which .betere said valve rcairclose4 upon .its seavt will. ,bear against the valve S and liftit froiiiitsseat. This,unseatingof'the valve S will communicate the vacuum within the channel T to the chamber containing the. pistoniL and the differential pressure acting upon said piston willlift the same, unseating the valve `L and seating the valve L2. The eifectis thereforetc open' the atmospheric air'connection to the receptacle B atsubstantially the samev timethat'the vacuum ispcut offffrom-saidreceptacle bythey closing` 0fthe valve J. The seating of the valve, L2, does not,- however,

completely prevent the passage ofj air through the port,v Q2, and lthence pastI the open valve,`S, and'through the passage T5' to the source of suction, whichvis usuallythe intake manifold ofthe engine, for the" reason that a bleed-portis formed by a.

Thisl bleed channel,v L3, in said valve, L2.' port is so restricted that'it does notinterl tere with the retention ofthe valve, L2,

against its seat asllong as the valve, S, is

open; but iipoii therclosing of said valve, S,

said bleed port, L3, will admit air to defeat the vacuum operating at the port Q, and permit the valve,r Q2, to drop away` from its sent.

The upward eXtensionV of the valve J is used for the performance of another important function, viz, that of -awmetering pin l tor variably restrict-ing` the port controlled by'lsaid valve. To this endy the member V is of slightly tapering form so that when the valve J is closed to its seat, thevacuum port will be greatly restricted. On the other hand, as the valve J recedes from its seat area'of the vacuum port will be progressivelyfincreased, attaining its maximum when the member ,V is completely withdrawnfrom1 the'p'oit.' 'Thisfhastlie effect ofy increasing the area of` vacuum connection to the chaine-v` berV B 'as the iioat Flowers, with a maximum area when the float occupies its lowest positio'n.` Itis, however,` desirable ,to only use this maximuiiiarea where the vacuum in the l manifold is very slight, and under normal, conditions to restrict ,the area, of connection. This is accomplished lay/forming an enlargement G" lon themstem lGr `which'closely fits withinJ the Abearing- I and ,acts K.as a` piston which is exposed to 'differential air pressures.

Thusu'when'the valve J isiirst withdrawn from itsr seat by .the downwardpull lofthe float, the frictionY of the, air passing between the piston L and bearing I'itow'ards the vacuum port will retard the downward" movement of the stem Gr. and,lin fact, wille hold the valve Jin close proximity to its seat.l The valve is. prevented `froin'coinpleteconnection to the receptacle Bwill'be highly restrict-ed; but when underexceptional con- Y ditions the vacuum is weak and the pneumatic pressure upon the piston L is thereby diminished, the valve J will be withdrawn lfarther from its seat, which'willenlarge the.

vacuum connection to the chamber B.v This enlarged vacuum port will communicate with the chamber B through a lateral port I in the bearing I which vis uncovered when the piston L drops to its lowermost position.

It is usual to arrangebetween the upper and lower chambers of the vacuum tank a gravity Aseated check valve which isnormally closed and is opened only by the pressure of the discharging` liquid. I have reversed Vthis condition by employing a check valve that is normally Aopen and is withdrawn from its seat by its own gravity. Gn the other hand,

when there is a vacuum in the receptacle B,

i the check valve must be closed, which is ac# complished by the following construction W is a fitting in the bot-tom of the receptacle B which receives the guide bearing H for the stem Gr and which also has a valve seat W. Below the valve seat lV is a chamber W2 which contains a valve X, preferably formed of sheet metal and preferably of an inverted cup form. Below the chamber W2 containing the valve Xris la contracted neck Y which may be formed of a separate member connected with the fitting W by a spun-over flange Y. The valve X will be arranged normally below the seat W so as to provide a free passage for the liquid from the receptacle B downward into the receptacle A. However, on account of the contracted neck Y, the wholelfitting will be filled with liquid during the discharge from the upper to the lower receptacle. Thus when through reversal of the valves J, S and L vacuum is placed in the upper receptacle, the atmospheric pressure in the lower re ceptacle will operate through the liquid column within the fitting W, reversing the direction of flow and carrying the valve X to its seat. The presence of this liquid within the fitting will thus greatly facilitate the movement of the valve so that a very slight change in pressure will cause either the opening or the closing of the valve. Vhen there is no liquid in the fitting, as where all the liquid in the upper receptacle has been drained out, then the enlarged vacuum connection to the receptacle B will` cause the rapid air current through the ittingVV, this impinging against the cupped valve and thereby lifting it to its seat.

With the construction as above described, the complete operation is as follows: It will be understood that the tank is connected in the usual way with the low level supply tank as through a conduit Z to the -intake manifold by the conduit- Ur and to the carburetor by the discharge conduit Z. Assuming that the vacuum tank yis empty, the float F will be in its lowermost position as shown in Figure l, in which position the valve J is with-V drawn from its seat and the metering pin V is withdrawn from obstructing the vacuum port. The valve L is also seated, closing the vent port M. When the engine is started, the throttle beingclosed, the high vacuum `will ber communicated through the conduit U to the chamber within the receptacle B. This will cause a rapidupward current ot' air through the iitting'lV, which current impinging against the valve X will lift the same to its seat. As soony as the valve X seats, the high vacuum within the receptacle B will cause the lifting of the liquid from the lower tank through the conduit Z and the filling of the receptacle B. As the level of the liquid rises in the receptacle B, the float F will be lifted by hydrostatic pressure, raising the stem G and piston G thereon so as to close the port I. Vhen this port is closed, the hydrostatic pressure on the iioat 'is supplemented by differential pneumatic pressure on the piston G, but the valve J is prevented from completely closing against its seat by the obstructionl of the valve S which in turn is held seated by dif-V ferential pneumatic pressure. Consequently, after the valve J has been moved into proximity to its seat, it will remain stationary until the rise of liquid in theV receptacle B 'will overcome the differential pneumatic pressure, unseating the valve S and seating the valve J. As soon as the valve S is unseated, the differential pressure thereon will be neutralized so that it is only the weight or the valve that bears upon the stem G. On the other hand, the differential pressure upon the valve J will retain the latter to its seat even after the level of liquid in the receptacle B has dropped belowl the displacement level for the float. The higher the vacuum which is operating uponthe valve J, the

longer the float will be held from droppino', and consequently, instead of' having absolutely Xed and determined high and low levels for the liquid, these will fluctuate according to vacuum conditions. It the vacuum is very light, the difference between the vupper and lower positions of the float will fbe slight and the reciprocations will be more rapid. On the other hand, if the vacuum is high, there will be a greater difference in vlevels and the reciprocation of the float will be slower.

When the Valve J seats and the valve S is unseated,'the vacuum communicated to the valve L2 and piston L will lift the valve L, opening the air port M and restoring atmospheric pressure within the receptacle B.

llU

This will permitJthefgyalvei X. to drop; by, its own2 gravity away.. from therseat .WC While the liquid nut-hinthe upper receptacle 'B isiiree-fto ilo-ranast .said Valve into `the lower tank. This continues until the liquid has reached a level nfhcrethe weight otthe iloat is less than the combined hydrostatic and;` pneumatic pressures, whereupon theV iioat aetl to seat. thus cut l oit 'trein the port rand .the bleed port i. wi ting. vthe Valve drops VunseatingV the valve land permitting the.,y Vacuum connection isv ieutralize the. vacuurmf. permit-cf( Sme Uy Mtl/flu "w L tu 'er1t lj' @fari y aid to thereby close theportflvl. Vacuum is zthenwi again communicated .to Vthefreceptacle: B.,and.

theL drop pressure in -thisjreceptacle Will'i canse axreversal of the liquid current inthe,

fitting lV, sothatthevalye is liit'ed to its seat.` Theiparts will remain in .this conditiony until thaliydrostatic pressurewon .the float.

willV overcome both-its Weight and the dii-ilerential -pneumatic pressure upon Vthe Valve; 5l

and the `icycleiis repeated Ithasheen stated that aidistui. unilormlcaribunetion is occasioned i by the functioning ottheiondinary vacuum tank, dueto alterationin maniftold pressuies the tankis alternately connected and' when .f

nected; Foiwinstanceywhen the tankl is conev nected With the manifold7 the air admittedl willreduce the vacuum and when it is disconnected7 the vacuum [will bel increased. "W ith my, improvement this yariation is largely eliminated bythe admission ofi air Yfrom the lexternal :atmosphere through the i bleed .port l? into the manifold duringtlie interval in which the tank is disconnected therefrom.; 1t' desi-red7 the quantity of air .so

' admitted canbemade toexactly balance the -quantity that is admitted irointlie vacuum chamber oit the tankso that thefcarburetor will not be disturbed .in its.4 action by the.;

shitting. of the tank valves.

Another important feature otniny inven-L tionais-theacceleration 1n the dischzuge` oi liquid. from the upper toithe lower; chambers.`

t ythe i tank .due i to i an unbroken` hydrostatic:

iulll and the action inzrespect tothe Velocitf,7

fion: vaniesssimilarly, to.. a f Siphon haiyingrl. a i variable length ot discharge.. Inother; words,r whenthe tankisnearest empty 'and there isthe ygreatestnecessitytor relilling,f the movement otV the liquid ytrom thev upper receptacle is accelerated and when. the lower tankv is nearly full,y the movementof theliqs uid troni the upper-receptacle is .less.rapi1d..

`What l claimasfmyv invention is:

l`r lia-a*vacuum.tank-having a connection. with a source i ot suction, Ymeans V-Ator connecte -said suction connection alternately with saidtank and vth'e.exterii'al .atmosphere to;I substantially balance]y the effect upon the `70 pressure fat JAhesouree oft suction..

Q'he conibinationuwith,1avacuum tank and a connection leading to awsource-otfsu l tieni intermittently .connected with said tank, ot 1 meansv operating; duringl the interval in 75 which'saidsuction connection is.-diseonneetedr tro-ni the tank to `admit theretoabalanci'ng volumeiotair;y f

3. Inra vacuum tank provided.with.anup-vv per and lower compartment, a Valve-conf 80 trolled port 'for liquid `flow from theiupper. to the: lower compartment, a; cond-uitv by which the liquid descends. by gravity from said port to its*discharge-inv theilower com# parti-nent, .sa-id conduit having flow capacityfs less than .the Valve-controlled port; so' that'.l the liquid in said conduit'constitutes-an'funbroken column whereby the Velocityioii dis-. charge is accelerated upon the lengthening. ot' said coliimn. 1'

il.. ln a `vacuum tank fpirovided with aniup-, per and a lower:compartment, a discharge-r connection Afrom said upper to saidfflower.' compartnient, .auiormally open check--ValaeA in saidI discharge connection, and a contract` 95 ed neck'below' said `checkfvalve for,'toi-ming.r an unbroken. liquid -columnsand.E for nor` e mally maintaining.liquidipressure` O11 both sides -oit `said valve..

5. ln a vacuum fueluteeding. system in100 combinatie-n with a receptacleprovidedfevitli aV liquid inlet, a,snctionnconnection and an atmospheric air fco'nnection`r and ai pneumat'v ically operated 'valwe controlling; said'atmos-r;

plier-ic: air connection, said Valve having a 105 x bleed port formed' therenn: avalve controlling said suction; connection,: and a movable member operated by pneumatic and hydroF static pressure for controlling'said vaines.l

ln testimony Whereoic l aiiix'my :signature:-

WILFRED O. CHASEL 

